Real knowledge is to know the extent of one's ignorance.

He who knows nothing is closer to the truth than he whose mind is filled with falsehoods and errors.

I was bold in the pursuit of knowledge, never fearing to follow truth and reason to whatever results they led, and bearding every authority which stood in their way.

Knowledge is love and light and vision.

If money is your hope for independence you will never have it. The only real security that a man will have in this world is a reserve of knowledge, experience, and ability.